To investigate effects of relative density of soil on pile stresses during soil liquefaction, dynamic centrifuge tests were performed on a superstructure-footing model supported by 2x2 piles. Additionally, pseudo-static analyses con-sidering embedment effect of footing were performed to evaluate the pile stresses. The following conclusions were reached: (1) The total earth pressure and the sidewall friction acting on the footing were in phase with the inertial force of superstructure in the loose sand. on the other hand, those were out of phase by 180 degrees with the inertial force in dens sand. (2) The estimated earth pressure and the sidewall friction acting on the footing and bending moment of the pile were in good agreement with the observed ones.